In 1998 health officials began seeing a new MRSA strain in people with no ties to health care settings. One major outbreak occurred in a prison.
Unlike the hospital-based MRSA, the community-based strain has been affecting healthy people.
"The fact that we're now seeing more infections among people without risk factors who are healthy represents a significant change in the epidemiology of this type of infection," Sara Zimmerman, an epidemiology specialist at the Mecklenburg County Health Department in Charlotte, North Carolina, said.
The community-based infections are usually more superficial and easier to treat than those in hospitals, and often resemble a pimple or a spider bite that can be red, swollen, and filled with pus.
If not treated appropriately, the infections can lead to serious infections of the blood or bone.
Health officials don't know how many people fall sick with the community-based MRSA. But the CDC's Coffin says about 25 percent of cases may result in hospitalization.
Gyms, Prisons, and Day Care Centers
Experts say the emergence of new MRSA strains shows the problem associated with antibiotics use.
"Due to the heavy use of antibiotics in Western medicine, these [staph] organisms have had the opportunity to develop mechanisms for resistance," Zimmerman said. "Unfortunately these organisms continue to exhaust our resources for combating these types of infections, making treatment options for clinicians very limited.
"Because this infection is so common, the focus has shifted to prevention and control versus eradication," she added.
MRSA is spread in two ways: by physical contact with an infected person or by touching inanimate objects like towels, linens, razors, or weightlifting equipment contaminated with bacteria.
It's not a disease that primarily affects athletes. But sports involving close contact, such as American football or wrestling, put athletes at higher risk for this infection.
Settings with close contact and lack of proper hygiene behaviors are particularly at risk, and prisons and day care centers may be highly vulnerable.
"Humans are reservoirs for staph," the CDC's Coffin said. "The most important thing for people to do is to keep an eye out for skin infections. Cover all wounds. If you have a skin infection, you should go to a doctor and have it looked at.
"Make sure your hands are clean, and don't share any personal items like towels and razors," she added.
After the outbreak among the St. Louis Rams players, officials there beefed up their defense against the disease by installing wall-mounted soap dispensers at the team's training facility and instructing players on how to care for wounds and how to monitor skin infections.
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